Ancient Sea Life May Have Hitched Across Oceans on Giant Living Rafts
by Raleigh McIlvery, Hakai Magazine, Smithsonian.com
Today’s oceans are jammed with plastic, which not only pollutes the water and poisons its inhabitants but also carries some animals to distant destinations. As researchers rush to discern the imminent repercussions of these virtually indestructible plastic rafts on global ecosystems, others are turning to the past to explore whether this buoyant lifestyle is actually new. The subject of their study? A giant of the Jurassic era: the crinoid.
Crinoids look more like plants than animals, but they are invertebrates related to sea stars and sea urchins. With floweresque crowns atop stems reaching 26 meters in length, crinoids living in the Jurassic were one of the world’s largest known invertebrates. In warm prehistoric seas, a subset of these behemoths used their anchor-like stems to grip floating logs and surf in colonies hundreds strong. And with them, life may have spread far and wide.
For marine and terrestrial organisms alike, rafting may be a key dispersal mechanism. In fact, rafting may have been one way islands like New Zealand were initially colonized by some organisms.